Video picture quality can be decreased by aliasing. Aliasing refers to defects or distortion in a video picture due to sampling limitations. The defects commonly appear as jagged edges on diagonal lines and twinkling or brightening (beating/pulsing) in picture detail.
In the H.264 specification, I-frame beating/pulsing is a significant problem, more so than with other video compression standards. The main source of the problem in H.264 is poor DC quantization in the coded bit stream. Poor DC quantization occurs because the H.264 specification does not provide explicit syntax to support finer DC quantization (i.e., quantization matrices and/or DC quantization).
The VC1 specification has separate quantization for AC and DC coefficients. However, VC1 does not have separately controllable quantization for every separate frequency component. The quantization of lower frequency AC coefficients can be relatively poor in VC1.
It would be desirable to implement a video encoder with a programmable quantization dead zone and thresholds for standard-based H.264 and/or VC1 video encoding.